Method for inhibiting cartilage degradation

ABSTRACT

A method of inhibiting cartilage degradation comprising administering to a human or other mammal in need of treatment an effective amount of a compound having the formula ##STR1## wherein R 1  and R 3  are independently hydrogen, ##STR2## wherein Ar is optionally substituted phenyl; R 2  is selected from the group consisting of pyrrolidino and piperidino, a pharmaceutically acceptable salt or solvate thereof.

BACKGROUND OF THE INVENTION

Cartilage is a proteinaceous material found in the joints of mammals. Itis an elastic, spongy substance which covers the articular surfaces ofthe bones within the synovial cavity. The presence of cartilage, withits special properties of compressibility elasticity and deformability,permits joints to carry out there two major functions which are to bareweight and to facilitate locomotion.

Degradation of joints occurs in various diseases including rheumitoidarthritis, psoriatic arthritis, osteoarthosis, hypertropic arthritis,and osteoarthritis. Further, acute inflammation of joints may beaccompanied by destruction of the cartilage. Examples of diseasesinvolving acute joint inflammation are yersinia arthritis, pyrophosphatearthritis, gout arthritis, and septic arthritis. Also, another factorthat may be conducive to destruction or degeneration of cartilage istreatment with cortisone

SUMMARY OF THE INVENTION

This invention provides methods for inhibiting cartilage degradation ina human or other mammal, comprising administering to a human or othermammal in need of treatment an effective amount of a compound of formulaI ##STR3##

wherein R¹ and R³ are independently hydrogen, ##STR4## wherein Ar isoptionally substituted phenyl;

R² is selected from the group consisting of pyrrolidino and piperidino;and pharmaceutically acceptable salts and solvates thereof.

DETAILED DESCRIPTION OF THE INVENTION

The current invention concerns the discovery that a select group of2-phenyl-3-aroylbenzothiophenes (benzothiophenes), those of formula I,are useful for inhibiting cartilage degradation. The methods oftreatment provided by this invention are practiced by administering to ahuman in need of inhibition of cartilage degradation a dose of acompound of formula I or a pharmaceutically acceptable salt or solvatethereof, that is effective to inhibit cartilage degradation. The terminhibit is defined to include its generally accepted meaning whichincludes phrophylactically treating a human subject to incurringcartilage degradation, and holding in check and/or treating existingcartilage degradation. As such, the present method includes both medicaltherapeutic and/or prophylactic treatment, as appropriate.

Generally, the compound is formulated with common excipients, diluentsor carriers, and compressed into tablets, or formulated as elixirs orsolutions for convenient oral administration, or administered by theintramuscular or intravenous routes. The compounds can be administeredtransdermally, and may be formulated as sustained release dosage formsand the like.

The compounds used in the methods of the current invention can be madeaccording to established procedures, such as those detailed in U.S. Pat.Nos. 4,133,814, 4,418,068, and 4,380,635 all of which are incorporatedby reference herein. In general, the process starts with abenzo[b]thiophene having a 6-hydroxyl group and a 2-(4-hydroxyphenyl)group. The starting compound is protected, acylated, and deprotected toform the formula I compounds. Examples of the preparation of suchcompounds are provided in the U.S. patents discussed above. Substitutedphenyl includes phenyl substituted once or twice with C₁ -C₆ alkyl, C₁-C₄ alkoxy, hydroxy, nitro, chloro, fluoro, or tri(chloro orfluoro)methyl.

The compounds used in the methods of this invention formpharmaceutically acceptable acid and base addition salts with a widevariety of organic and inorganic acids and bases and include thephysiologically acceptable salts which are often used in pharmaceuticalchemistry. Such salts are also part of this invention. Typical inorganicacids used to form such salts include hydrochloric, hydrobromic,hydrochloric, nitric, sulfuric, phosphoric, hypophosphoric and the like.Salts derived from organic acids, such as aliphatic mono anddicarboxylic acids, phenyl substituted alkanoic acids, hydroxyalkanoicand hydroxyalkandioic acids, aromatic acids, aliphatic and aromaticsulfonic acids, may also be used. Such pharmaceutically acceptable saltsthus include acetate, phenylacetate, trifluoroacetate, acrylate,ascorbate, benzoate, chlorobenzoate, dinitrobenzoate, hydroxybenzoate,methoxybenzoate, methylbenzoate, o-acetoxybenzoate,naphthalene-2-benzoate, bromide, isobutyrate, phenylbutyrate,β-hydroxybutyrate, butyne-1,4-dioate, hexyne-1,4-dioate, caprate,caprylate, chloride, cinnamate, citrate, formate, fumarate, glycollate,heptanoate, hippurate, lactate, malate, maleate, hydroxymaleate,malonate, mandelate, mesylate, nicotinate, isonicotinate, nitrate,oxalate, phthalate, teraphthalate, phosphate, monohydrogenphosphate,dihydrogenphosphate, metaphosphate, pyrophosphate, propiolate,propionate, phenylpropionate, salicylate, sebacate, succinate, suberate,sulfate, bisulfate, pyrosulfate, sulfite, bisulfite, sulfonate,benzene-sulfonate, p-bromophenylsulfonate, chlorobenzenesulfonate,ethanesulfonate, 2-hydroxyethanesulfonate, methane-sulfonate,naphthalene-1-sulfonate, naphthalene-2-sulfonate, p-toluenesulfonate,xylenesulfonate, tartarate, and the like. A preferable salt is thehydrochloride salt.

The pharmaceutically acceptable acid addition salts are typically formedby reacting a compound of formula I with an equimolar or excess amountof acid. The reactants are generally combined in a mutual solvent suchas diethyl ether or benzene. The salt normally precipitates out ofsolution within about one hour to 10 days and can be isolated byfiltration or the solvent can be stripped off by conventional means.

Bases commonly used for formation of salts include ammonium hydroxideand alkali and alkaline earth metal hydroxides, carbonates andbicarbonates, as well as aliphatic and aromatic amines, aliphaticdiamines and hydroxy alkylamines. Bases especially useful in thepreparation of addition salts include ammonium hydroxide, potassiumcarbonate, sodium bicarbonate, calcium hydroxide, methylamine,diethylamine, ethylene diamine, cyclohexylamine and ethanolamine.

The pharmaceutically acceptable salts generally have enhanced solubilitycharacteristics compared to the compound from which they are derived,and thus are often more amenable to formulation as liquids or emulsions.

Pharmaceutical formulations can be prepared by procedures known in theart. For example, the compounds can be formulated with commonexcipients, diluents, or carriers, and formed into tablets, capsules,suspensions, powders, and the like. Examples of excipients, diluents,and carriers that are suitable for such formulations include thefollowing: fillers and extenders such as starch, sugars, mannitol, andsilicic derivatives; binding agents such as carboxymethyl cellulose andother cellulose derivatives, alginates, gelatin, and polyvinylpyrrolidone; moisturizing agents such as glycerol; disintegrating agentssuch as agaragar, calcium carbonate, and sodium bicarbonate; agents forretarding dissolution such as paraffin; resorption accelerators such asquaternary ammonium compounds; surface active agents such as cetylalcohol, glycerol monostearate; adsorptive carriers such as kaolin andbentonite; and lubricants such as talc, calcium and magnesium stearate,and solid polyethyl glycols.

The compounds can also be formulated as elixirs or solutions forconvenient oral administration or as solutions appropriate forparenteral administration, for instance by intramuscular, subcutaneousor intravenous routes. Additionally, the compounds are well suited toformulation as sustained release dosage forms and the like. Theformulations can be so constituted that they release the activeingredient only or preferably in a particular part of the intestinaltract, possibly over a period of time. The coatings, envelopes, andprotective matrices may be made, for example, from polymeric substancesor waxes.

The particular dosage of a compound of formula I required to inhibitcartilage degradation, according to this invention will depend upon theseverity of the condition, the route of administration, and relatedfactors that will be decided by the attending physician. Generally,accepted and effective daily doses will be from about 0.1 to about 1000mg/day, and more typically from about 50 to about 200 mg/day. Suchdosages will be administered to a subject in need of treatment from onceto about three times each day, or more often as needed to effectivelyinhibit cartilage degradation.

It is usually preferred to administer a compound of formula I in theform of an acid addition salt, as is customary in the administration ofpharmaceuticals bearing a basic group, such as the piperidino ring. Itis also advantageous to administer such a compound by the oral route toan aging human (e.g. a post-menopausal female). For such purposes thefollowing oral dosage forms are available.

Formulations

In the formulations which follow, "Active ingredient" means a compoundof formula I.

    ______________________________________                                        Formulation 1: Gelatin Capsules                                               Hard gelatin capsules are prepared using the following:                       Ingredient        Quantity (mg/capsule)                                       ______________________________________                                        Active ingredient 0.1-1000                                                    Starch, NF        0-650                                                       Starch flowable powder                                                                          0-650                                                       Silicone fluid 350 centistokes                                                                  0-15                                                        ______________________________________                                    

The ingredients are blended, passed through a No. 45 mesh U.S. sieve,and filled into hard gelatin capsules.

Examples of specific capsule formulations of the compound of formula 1wherein R² is piperidino, (raloxifene), that have been made includethose shown below:

    ______________________________________                                        Ingredient        Quantity (mg/capsule)                                       ______________________________________                                        Formulation 2: Raloxifene capsule                                             Raloxifene        1                                                           Starch, NF        112                                                         Starch flowable powder                                                                          225.3                                                       Silicone fluid 350 centistokes                                                                  1.7                                                         Formulation 3: Raloxifene capsule                                             Raloxifene        5                                                           Starch, NF        108                                                         Starch flowable powder                                                                          225.3                                                       Silicone fluid 350 centistokes                                                                  1.7                                                         Formulation 4: Raloxifene capsule                                             Raloxifene        10                                                          Starch, NF        103                                                         Starch flowable powder                                                                          225.3                                                       Silicone fluid 350 centistokes                                                                  1.7                                                         Formulation 5: Raloxifene capsule                                             Raloxifene        50                                                          Starch, NF        150                                                         Starch flowable powder                                                                          397                                                         Silicone fluid 350 centistokes                                                                  3.0                                                         ______________________________________                                    

The specific formulations above may be changed in compliance with thereasonable variations provided.

A tablet formulation is prepared using the ingredients below:

    ______________________________________                                        Formulation 6: Tablets                                                        Ingredient       Quantity (mg/tablet)                                         ______________________________________                                        Active ingredient                                                                              0.1-1000                                                     Cellulose, microcrystalline                                                                    0-650                                                        Silicon dioxide, fumed                                                                         0-650                                                        Stearate acid    0-15                                                         ______________________________________                                    

The components are blended and compressed to form tablets.

Alternatively, tablets each containing 0.1-1000 mg of active ingredientare made up as follows:

    ______________________________________                                        Formulation 7: Tablets                                                        Ingredient          Quantity (mg/tablet)                                      ______________________________________                                        Active ingredient   0.1-1000                                                  Starch              45                                                        Cellulose, microcrystalline                                                                       35                                                        Polyvinylpyrrolidone                                                                              4                                                         (as 10% solution in water)                                                    Sodium carboxymethyl cellulose                                                                    4.5                                                       Magnesium stearate  0.5                                                       Talc                1                                                         ______________________________________                                    

The active ingredient, starch, and cellulose are passed through a No. 45mesh U.S. sieve and mixed thoroughly. The solution ofpolyvinylpyrrolidone is mixed with the resultant powders which are thenpassed through a No. 14 mesh U.S. sieve. The granules so produced aredried at 50°-60° C. and passed through a No. 18 mesh U.S. sieve. Thesodium carboxymethyl starch, magnesium stearate, and talc, previouslypassed through a No. 60 U.S. sieve, are then added to the granuleswhich, after mixing, are compressed on a tablet machine to yieldtablets.

Suspensions each containing 0.1-1000 mg of medicament per 5 mL dose aremade as follows:

    ______________________________________                                        Formulation 8: Suspensions                                                    Ingredient           Quantity (mg/5 ml)                                       ______________________________________                                        Active ingredient    0.1-1000  mg                                             Sodium carboxymethyl cellulose                                                                     50        mg                                             Syrup                1.25      mg                                             Benzoic acid solution                                                                              0.10      mL                                             Flavor               q.v.                                                     Color                q.v.                                                     Purified water to    5         mL                                             ______________________________________                                    

The medicament is passed through a No. 45 mesh U.S. sieve and mixed withthe sodium carboxymethyl cellulose and syrup to form a smooth paste. Thebenzoic acid solution, flavor, and color are diluted with some of thewater and added, with stirring. Sufficient water is then added toproduce the required volume.

ASSAY #1

Rabbit articular chondrocytes are placed in culture. Variousconcentrations of the compound of the invention (10⁻⁹ M to 10⁻⁵ M) andSodium ³⁵ [S]ulfate are added to the culture simultaneously inserum-free medium. After 48 hours, the amount of radiolabel incorporatedinto the cell and matrix (extracted with 4M guanidinium chloride) isevaluated and compared against control cells, to determine effect ofcompounds on proteoglycan synthesis.

ASSAY #2

Rabbit articular chondrocytes are treated with various concentrations ofthe compounds of the invention (10⁻⁵ M to 10⁻⁵ M) in the presence andabsence of a constant concentration of estrogen (10⁻⁸ M), andproteoglycan synthesis is evaluated as described above.

ASSAY #3

Rabbit chondrocytes are isolated and radiolabled as in Assay 1 above.The cells are then treated with interleukin-1β(10 ng/mL) for 24-72 hoursboth with and without a compound of the invention. The loss ofproteoglycan in each of the cell cultures is observed. Active compoundswill block the loss of proteoglycan.

ASSAY #4

Bovine cartilage is cut into 5 by 1 mm slices and labeled with sodium ³⁵[S]ulfate for 48 hours and then treated as in Assay 3. Active compoundsare expected to block the loss of proteoglycan from cartilage.

ASSAY #5

In order to evaluate whether the compounds of the invention induceTGF-βs(1, 2, 3), rabbit chondrocytes are treated for 24-72 hours withvarious concentrations of compounds of the invention and the conditionedmedia is assayed for the presence of latent and active TGF-βs.

ASSAY #6

Rabbit chondrocytes are treated with interleukin-1β(10 ng/ml) for 48 hin serum-free medium in the presence and absence of a comound of theinvention. At the end of the incubation period, the medium is removedand assayed for neutral protease activity, using ³ [H]-casein assustrate for the enzyme activity. An active comound inhibits theproduction and/or activity of the enzyme induced by interleukin-1.

ASSAY #7

C₅₇ B1 mice receive intermittent subcutaneous injections with a compoundof the invention beginning at one to six months of age. The course oftreatment continues for 6-12 months. The animals are sacrificed at 18-20months of age and their knee joints are evaluated for evidence ofosteoarthritis. Decreased incidence or severity of osteoarthritis damageis indication of the efficacy of treatment.

Activity in any of the above assays indicates that compounds in theinvention are useful in the inhibition of cartilage degradation.

We claim:
 1. A method of inhibiting cartilage degradation comprisingadministering to a human or other mammal in need of treatment aneffective amount of a compound having the formula ##STR5## wherein R¹and R³ are independently hydrogen, ##STR6## wherein Ar is optionallysubstituted phenyl; R² is selected from the group consisting ofpyrrolidino and piperidino; or a pharmaceutically acceptable salt orsolvate thereof.
 2. The method of Claim 1 wherein said compound is thehydrochloride salt thereof.
 3. The method of Claim 1 wherein saidcompound is ##STR7## or its hydrochloride salt.